The terms "thiuronium" and "isothiouronium" appear to be used interchangeably in the art to describe salts formed by reacting a thiourea with an alkylating agent. Such salts will be referred to hereafter as isothiouronium salts.
Loev et al. describe a class of isothiouronium halides which they prepared by reacting an alkylated benzyl halide (e.g., dodecylbenzylchloride) with a N,N,N',N'-tetraalkylthiourea (e.g., N,N,N',N'-tetramethylthiourea). Loev et al indicated that the compounds were useful as surfactants, a property they illustrated by shaking the compounds in water and observing the formation of a foam.
Other isothiouronium salts and methods of preparing same are described by Teramura et al. in U.S. Pat. No. 3,721,581. The isothiouronium salts are there used as flameproofing agents.